N. V. Morozova

An Effect of Interelectrode Potentials on an Afterpulse Formation in a Photomultiplier Tube

An effect of the interelectrode potential difference on the intensity of the afterpulse formation in a XP2020 photomultiplier tube is studied; the afterpulses are caused by an ion feedback. It is shown that the photocathode–accelerating-electrode gap plays a decisive role in the process, while the dynode system is of minor importance at pulse currents below a few dozens of milliamperes.

A Two-Detector Single-Crystal Scintillation Autocorrelation Spectrometer with Rejection of Afterpulses

A two-detector single-crystal scintillation autocorrelation spectrometer with rejection of afterpulses has been developed. Afterpulses are rejected by the delayed coincidence method.

A Maximal Afterpulse Amplitude-to-Main Pulse Amplitude Ratio in a Photomultiplier Tube

An amplitude dependence of afterpulses caused by an ion feedback on the main pulse amplitudes in a photomultiplier tube is studied. It has been found that a maximal afterpulse amplitude-to-maximal main pulse amplitude ratio is inversely proportional to the main pulse amplitude. It has been discovered that the feedback-ion intensities are proportional to the charge released by main pulses at the output of the photomultiplier tube. These facts prove that a detection process of single ions can explain the maximal amplitudes of afterpulses.

Gas discharge processes in metal channel and standard photomultiplier tubes

The effect of the potential difference at the focusing chamber electrodes of XP2020, FEU-85, FEU-87, and FEU-93 photomultiplier tubes on the intensity of afterpulses resulting from gas discharge processes is investigated. The time distributions of afterpulses in H6780 and R7600U-200 metal channel photomultiplier tubes are also analyzed.

A Time-Stability Control System for the Delayed-Coincidence Scintillation Spectrometer

The system for time-stability control of a delayed-coincidence scintillation spectrometer is based on LEDs and an optical delay line. Using this system, it is possible to control the time stability of the spectrometer with an accuracy of ±3.6 ps and measure the lifetimes of radioactive-nuclei levels by a shift of the centroids of instantaneous- and delayed-coincidence curves over a picosecond range.

A new method for measuring γ-ray energy at the internal calibration of a radioactive source

We developed a new method for measuring γ-ray energies in the internal calibration of a radioactive source under investigation. The measurements were carried out with the spectrometer of delayed coincidences and an optical delay line. This method allows the energies of the reference peak and the γ-ray peak under investigation to be compared, even if they are close or coincide. The possibility of precise γ-ray energy measurements is illustrated with60Co and154Eu isotopes.

Quasi-differentiation method for forming anti-Compton γ-ray spectra

A method for forming anti-Compton γ-ray spectra is considered. The method is based on the quasi-differentiation of experimental γ-spectra according to the peak width.